1. Field of the Invention
The invention relates to solvents for loosening or removing cured fiberglass resin from tools, processing equipment and other substrates.
2. Description of Related Methods
A variety of solvents have been used to clean processing equipment, metal parts and tools after a polyester resin (fiberglass) has cured on them. Acetone, methyl ethyl ketone, and diacetone alcohol are the solvents most commonly used to remove cured polyester resin from the substrates to which it is attached. However, acetone and methyl ethyl ketone are not favored because of safety hazards resulting from their high volatilities and low flash points. Additionally, acetone and methyl ethyl ketone currently are suspected neurotoxins. Diacetone alcohol is very polar, and therefore presents processing problems when used alone. Thus, it would be a substantial improvement in the art if a relatively inexpensive yet effective solvent formulation were available to remove cured polyester resins from substrates, and that reduced or avoided the environmental, health and safety problems of the prior art solvent formulations.
Applicant has discovered, surprisingly, that a cured polyester resin may be removed from a substrate by contacting the polyester resin with an alkylene carbonate, alone or as a co-solvent in a mixture containing one or more other solvents. The present inventive process, by substituting, in whole or in part, alkylene carbonate for the more hazardous prior art solvents, reduces or avoids many of the health, safety and environmental hazards associated with the prior art solvents, and is economically attractive as well.